As highly functional wireless terminals such as smartphones and tablet computers have become widespread, and broadband wireless communication services such as Long Term Evolution (LTE), public wireless local area network (WLAN), and the like are also widespread, instant messaging (IM) services have been widely used (e.g., see Patent Literature 1 and 2) in wireless terminals. IM provides real-time text-based communication among a plurality of users using the same IM application. Wireless terminals used by these users execute the same IM application. IM may be referred to as mobile messaging, text chat, text-based messaging, or interactive messaging.
In the present specification, an application that provides text or text-based messaging among a plurality of online users using the same application, regardless of whether or not it is specialized in IM, is defined as an IM application. Typical examples of the IM application are LINE, WhatsApp, Text Me!, Viber, Kakao Talk, Skype, Google Hangouts, iMessage, Twitter, Facebook, and the like. The names of these IM applications are trademarks or registered trademarks of the operators of the respective IM services.
IM is provided via an IM server system managed by the operator of the IM service. Specifically, a wireless terminal of a first user using the IM application transmits a message destined for a second user to the IM server system. Then, the IM server system transmits this message destined for the second user to a wireless terminal of the second user using the same IM application.
Further, some IM services offer special accounts different from normal user accounts (hereinafter referred to as normal accounts) that are assigned to normal users. The special accounts have authority to broadcast a message to many more accounts than the normal accounts do. For example, the special accounts are assigned to government offices, commercial enterprises, commercial facility operators, publishers, broadcasting organizations, and the like and are used to widely distribute information regarding public services, products, commercial services, magazines, television programs, etc. to a large number of users.
For example, a web-based operation is used to send a message originated by the special account (hereinafter referred to as a special message). Specifically, a user of the special account accesses the IM server system (web server) using a web browser and sends a special message through a web-based management screen.
Moreover, a mechanism that allows a wireless terminal in which the normal account has been set to send special messages has also been provided. Specifically, the user of the special account registers, in the IM server system, one or more normal accounts used to send special messages. In an example, the IM server system may provide each special account with a bot account for sending special messages. In this case, the user of each special account registers the corresponding bot account, which is used for sending special messages, in an account list (which is commonly referred to as friends or buddies) of a normal account and requests the bot account to register this normal account in an account list (friends or buddies) of the bot account. The bot account requests the user to enter a password when registering the normal account. This password is issued to the user of the special account by the IM service operator and the user can obtain it, for example, through the web-based management screen of the special account. After the normal account is successfully registered in the account list (friends or buddies) of the bot account, the user of the special account sends a message destined for the bot account from the registered normal account. The IM server system delivers this message, which has been received by the bot account from the registered normal account, to receivers associated with the special account as a special message.